Displacement Changing Control Device for Scroll Compressors

ABSTRACT

Aiming at the problem of the difficulty in changing the displacement of vehicle scroll compressors, this invention opens a displacement changing control device for scroll compressors that is good for the quick start of the compressor, and can conveniently control the displacement and pressure of the compressor within the set range, and can be used with various kinds of scroll compressors. It includes the case ( 1 ). A piston barrel ( 3 ) that is used to install the piston control valve ( 2 ) that is set in the case ( 1 ). An air-intake channel ( 4 ) that connects with the piston barrel ( 3 ), high pressure feedback channel ( 7 ) and displacement adjustment channel ( 9 ) that are set on the piston barrel. The piston control valve ( 2 ) is located between the air-intake channel ( 4 ) and the high pressure feedback channel ( 7 ). A spring ( 10 ), which has one end that resists the piston control valve ( 2 ), is installed in the air-intake channel ( 4 ). A corrugated pipe pressure control valve ( 11 ) is installed on the center of the piston control valve ( 2 ). A balance pipe ( 12 ) is installed in the described high pressure feedback channel ( 7 ). It enjoys the advantages of a simple structure, good safety and high reliability.

CROSS REFERENCE TO RELATED PATENT APPLICATION

This application claims a priority of the Chinese patent application No. 200610096136.2, filing date Sep. 22, 2006.

FIELD OF THE INVENTION

This invention relates to a scroll compressor, especially to a displacement changing scroll compressor for vehicles. To be more specific, it is a displacement changing control device for scroll compressors.

BACKGROUND OF THE INVENTION

Currently, scroll compressors are the preferred air conditioner compressors for automobiles and household air conditioners because of advantages such as small sizes, large power, good safety, high reliability, etc.

For vehicles' compressors, the increase of the vehicle's speed will cause the speed of the dynamic disc to increase correspondingly, and the displacement of the compressor will also increase. The discharge pressure will increase rapidly and exceed the working value set by the system. Therefore, in order to guarantee the normal working of the air conditioning system, the compressor must immediately stop operating or carry out a displacement adjustment so as to avoid the damage caused by excessive pressure. If we stop the compressor to decrease the pressure and the displacement, the compressor clutch will start and stop frequently, and loud noises will be caused. If we adopt the method of pressure relief after excessive pressure, the efficiency of the system will be decreased, and environment pollution will be caused. Therefore, people often adopt the method of introducing the high pressure air in the high pressure cavity to the air-intake cavity to adjust the displacement of the compressor. In this way, people can control the output pressure of the compressor by changing the displacement. However, the pressure in the high pressure cavity is high, and the actual control effect is not good. It will be easy to cause a low starting efficiency for the air compressor. Thus, it will influence the refrigeration and warming effect. This problem has limited the development of scroll compressors for vehicles for a long period of time.

SUMMARY OF THE INVENTION

The aim of this invention is to solve the problem of difficult displacement changing for vehicles' scroll compressors and to design a displacement changing control device for scroll compressors that can be used together with various kinds of scroll compressors, which is good for the rapid start of compressor and can conveniently control the displacement and pressure of the compressor within a design range.

The Technical Scheme of this Invention is as Follows:

A displacement changing control device for scroll compressors. It includes the case (1). A piston barrel (3) that is used to install the piston control valve (2) is set in the case (1). An air-intake channel (4) that connects with the piston barrel (3), high pressure feedback channel (7) and displacement adjustment channel (9) are set on the piston barrel. The air-intake channel (4) connects with the air-intake cavity (21) of the scroll compressor. The high pressure feedback channel (7) connects with the high pressure cavity (6) on the static disc (5) of the scroll compressor. The displacement adjustment channel (9) connects with the pre-pressing cavity (8) of the static disc (5) of the scroll compressor. The piston control valve (2) is located between the air-intake channel (4) and the high pressure feedback channel (7). A spring (10), which has one end that resists the piston control valve (2), is installed in the air-intake channel (4). A corrugated pipe pressure control valve (11) is installed in the center of the piston control valve (2). A balance pipe (12) is installed in the described high-pressure feedback channel (7).

The balance pipe (12) can adopt the capillary pipe for compressors.

The balance pipe (12) can also be composed of a pipe case (13), filter screen (14), sealing ring (15) and interception pipe (16). A through-hole (17) is set on the center of the interception pipe (16). The sealing ring (15) is installed in the ring flute (18) that is in the middle of the pipe case (13). One air-inlet cavity (19) and air-out cavity (20) that is composed of one axial direction rib on the pipe case (13) and the filter screen (14) covered on this axial direction rib are set on the two sides of the sealing ring (15). The interception pipe (16) is installed in the pipe case (16). One of its ends is located in the air-inlet cavity (19), and the other end is located in the air-out cavity (20).

The diameter of the through-hole 17 is 0.1˜0.7 mm,

The number of holes in the filter screen is ≦180 per inch.

This Invention Enjoys the Following Advantages:

This invention realizes the aim of changing the displacement through discharging the medium to the air-intake cavity before compression. It drastically changes the conventional concept of changing the displacement through the high pressure cavity, which lasted for a long time. It is a revolutionary breakthrough in the concept of displacement changing for compressors. At the same time, it enjoys the following advantages: simple structure, reliable control, low starting moment, high speed, low resistance, and the displacement and pressure of compression are not influenced by the speed of vehicle. It is good for reducing noise and increasing efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is the structural representation of this invention

FIG. 2 is the A direction view of the FIG. 1.

FIG. 3 is the position view of the piston control valve in the displacement changing control device of this invention when the scroll compressor is not operating.

FIG. 4 is the position view of the piston control valve in the displacement changing control device of this invention when the scroll compressor is at the preliminary stage of starting and at the full displacement operating status.

FIG. 5 is the position view of the piston control valve in the displacement changing control device of this invention at the moving moment in the piston barrel when the scroll compressor is operating at the super high speed.

FIG. 6 is the principle schematic drawing of the corrugated tube pressure control valve of this invention.

FIG. 7 is the structural representation of the balance pipe of this invention.

DETAILED DESCRIPTION OF THE INVENTION

The following is the further explanation on this invention combining the structure drawing and implementation example.

Refer to FIGS. 1, 2, and 6.

A displacement changing control device for scroll compressors. It includes the case 1, and a piston control valve 2. The case 1 connects with the static disc 5 of the scroll compressor. A piston barrel 3, that is used to install the piston control valve 2, is set in the case 1. An air-intake channel 4 that connects with the piston barrel 3, high pressure feedback channel 7 and displacement adjustment channel 9 are set on the piston barrel. The air-intake channel 4 connects with the air-intake cavity (21) of the scroll compressor. The high pressure feedback channel 7 connects with the high pressure cavity 6 on the static disc 5 of the scroll compressor. The displacement adjustment channel 9 connects with the pre-pressing cavity 8 of the static disc 5 of the scroll compressor. The pre-pressing cavity 8 is located at the binding site between the air-intake cavity and compression cavity. Each compressor has two pre-pressing cavities, on the left and right. As FIG. 2 shows, the piston control valve 2 is located between the air-intake channel 4 and the high pressure feedback channel 7. As FIG. 1 shows, a spring 10, which has one end of that resists the piston control valve 2 is installed in the air-intake channel 4. A corrugated pipe pressure control valve 11 is installed on the center of the piston control valve 2 (Model 3 or model 7 corrugated pipe pressure control valve manufactured by Japan Yigeer Co., Ltd. (

) may be adopted, refer to FIG. 6 for details). A balance pipe 12 that is made from capillary pipe is installed in the described high pressure feedback channel 7.

When actual implementation is carried out, the balance tube 12 can also be composed of a pipe case 13, filter screen 14, sealing ring 15 and interception pipe 16. A through-hole 17 with the diameter of 0.37 mm is set on the center of the interception pipe 16. As FIG. 7 shows, the sealing ring 15 is installed in the ring flute 18 that is in the middle of the pipe case 13. One air-inlet cavity 19 and air-out cavity 20 that is composed of one axial direction rib on the pipe case 13 and the filter screen 14 (filter screen with about 140 holes may be adopted) covered on this axial direction rib are set on the two sides of the sealing ring 15. The interception pipe 16 is installed in the pipe case 16. One of its ends is located in the air-inlet cavity 19, and the other end is located in the air-out cavity 20. After the high pressure medium (air) in the high pressure cavity enters the high pressure feedback channel 7, it will bypass the end of the pipe case 13 of the balance pipe 12 and then enter the air-inlet cavity 19 from the filter screen 14 on the side. Then, it will flow out from the other end of the air-out cavity 20 through the pressure relief effect of the through-hole 17 with a very small diameter. Next, it will enter the piston barrel 3 through the filter screen. In this way, the pressure of the air that enters the piston barrel 3 will be greatly decreased through the lag and pressure relief effect of the interception pipe 16 so as to meet the working requirements of the piston control valve 2 and the corrugated pipe pressure control valve 11 that is installed on the piston control valve 2. At the same time, it can make the displacement changing control of this invention more reliable.

The Working Process of this Invention is as Follows:

As FIG. 3 shows, before the compressor starts working, Pd (pressure of the high pressure cavity), Ps (pressure of the air-intake cavity 21), Q1 and Q2 (pressure of the pre-pressing cavity) are zero. At this moment, the piston control valve 2 is located at one end of the piston barrel 3 with the effect of the spring 10 (refer to FIG. 3 for details), and the air-intake channel 4 and the displacement adjustment channel 9 connect each other. Therefore, the starting moment is very small.

After the compressor starts working, the discharge pressure will gradually increase. At this moment, the pressure in the feedback channel 7 will increase and drive the piston control valve 2 to overcome the effect of the spring 10 to block the displacement adjustment channel 9. Refer to FIG. 4 for details. At this moment, the compressor is at the full displacement working status.

When the speed of the vehicle increases rapidly and the compressor is operating at a super high speed, as the air-intake pressure is decreased, the pressure in the air-intake channel 4 will be decreased. At the same time, the pressure in the high pressure feedback channel 7 will increase constantly. When the pressure difference between them meets the action condition of the corrugated pipe pressure control valve 11 that is installed in the piston control valve 2, the corrugated pipe pressure control valve 11 will begin taking action to fully or partially connect the air-intake channel 4 and high pressure feedback channel 7. Thus, the pressure at the end of the piston control valve 2 that corresponds to the high pressure feedback channel 7 will decrease, and the piston control valve 2 will move upward and downward because of the spring 10. In this way, the displacement adjustment channel 9 will connect with the air-intake channel 4. Refer to FIG. 5 for details. The size of the opening is related to the pressure of the spring 10, the discharge pressure of the compressor's high pressure cavity, and the setting pressure of the corrugated pipe pressure control valve 11. Contrarily, when the pressure in the compressor's high pressure discharge cavity decreases, the corrugated pipe pressure control valve 11 will stop working, and the piston control valve 2 will move toward the direction of reducing the opening until the acting forces on the two ends of the piston control valve 2 are balanced. The compressor can be kept at the best refrigerating or warming status through the rational configuration of these three factors. 

1. A displacement changing control device for scroll compressors including a case, a piston barrel used for installing a piston control valve being in the case, an air-intake channel connected with the piston barrel, a high pressure feedback channel and a displacement adjustment channel being set on the piston barrel, the air-intake channel connecting an air-intake cavity of the scroll compressor, the high pressure feedback channel connecting a high pressure cavity on a static disc, the displacement adjustment channel connecting pre-pressing cavitys of the static disc, a piston control valve located between the air-intake channel and the high pressure feedback channel, a spring having one end resisting the piston control valve being installed in the air-intake channel, a corrugated pipe pressure control valve installed in the center of the piston control valve, a balance pipe installed in the high-pressure feedback channel.
 2. The displacement changing control device for scroll compressors of claim 1, wherein the balance pipe is a capillary pipe.
 3. The displacement changing control device for scroll compressors of claim 1, wherein the balance pipe includes a pipe case, a filter screen, a sealing ring and a interception pipe, a through-hole is set in the interception pipe, the sealing ring is installed in a ring flute located at the middle of the pipe case, an air-inlet cavity and an air-out cavity both covered filter screen are set on two sides of the sealing ring, the interception pipe is installed in the pipe case, and connecting the air-inlet cavity with the air-out cavity.
 4. The displacement changing control device for scroll compressors of claim 3, wherein the diameter of the through-hole is 0.1-0.7 mm.
 5. The displacement changing control device for scroll compressors of claim 3, wherein the size of the filter screen is ≦180 hole per inch. 